Signal and control circuits for dishwashing apparatus



March 4, 1958 F. D. LOW

SIGNAL AND CONTROL CIRCUITS FOR DISHWASHING APPARATUS 2 Sheets-Sheet 1 Filed Nov. 29, 1955 MMSI/H076 /07 mm? Mom/f INVENTOR.

y' mn/rllLaw SIGNAL. AND CONTROL. CIRCUITS FOR DISRWASHING APPARATUS Filed Nov. 29, 1955 F. D. LOW

March 4, 1958 2 Sheets-Sheet '2 INVENTOR. .Ffm/r ./2 Low @my @f m /J/j/s By gmk;

United States atent' SIGNAL AND CONTROL CIRCUITS FOR DISHWASHING APPARATUS Frank D. Low, La Grange Park, Ill., assigner to General Electric Company, a corporation of New York Application November 29, 1955, Serial No. 549,621

' s claims. (c1. 134-53) The present invention relates to signal and control circuits for dishwashing apparatus; and it is the general object of the invention to provide such a circuit in corporating an improved signal arrangement that is governed by the program controller for the dishwashing apparatus.

Another object of the invention is to provide a signal and control circuit of the character noted, that comprises a run pilot signal that is operated to indicate that the washing cycle is in progress and a cycle pilot signal that is operated to indicate that the washing cycle has been completed.

Another object of the invention is to provide a signal and control circuit of the character noted, that embodies a gaseous discharge tube arrangement for the cycle pilot.Y

Further features of the invention pertain to the particular arrangement of the elements of the signal and control circuit for the dishwashing apparatus, whereby the above-outlined and additional operating features thereof are attained. v

The invention, both as to its organization and method of operation, together with further objects and advantages thereof will bestibe understood by reference to thefollowing specitication taken in connection with the accompanying drawings, in which:

Figure l is a front elevational view, partly broken away, of dishwashing apparatus incorporating a signal and control circuit embodying the present invention;

Fig. 2 is a vertical sectional view of the dishwashing apparatus, taken in the'direction of the arrows along the offset line 2-2 in Fig. 1;

Fig. 3 is a diagrammatic illustration of the signal and control circuit incorporated in the dishwashing apparatus shown in Figs. l and 2;

Fig. 4 is an enlarged fragmentary vertical sectional View ofan electro-responsive combined water control valve and controlswitch that is embodied in the dishwashing apparatus of Figs. l and 2 and incorporated in the signal and control circuit of Fig. 3;

Fig. 5 is a combined time-sequence operation chart of the elements incorporated in the signal and control circuit of Fig. 3; and

Fig. 6 is a diagrammatic illustration of a fragmentary portion of a modified form ot the signal and control circuit of Fig. 3.

Referring now to Figs. 1 and 2 of the drawings, there `is generally illustrated dishwashing apparatus 10 of the character of that disclosed in U. S. Patent No. 2,620,811,

granted on 'December 9, 1952, to Forrest A. Walker,A and prises an upstanding cabinet 11 housing an upstanding Y vat 12, the cabinet 11 and the vat 12 being provided with aligned upstanding front openings therein that are, in turn, provided with an upstanding front door 13. The

front door 13 is pivotally mounted adjacent to the lower edge thereof within the lower front opening of the vat 12 and is movable between a substantially vertical closed position and a substantially horizontal open position. A

pocket 13a is formed in the lower central portion of the 'inner wall of the front door 13 and arranged toreceive a quantity of detergent that is employed in the washing of= the dishes. Also, the apparatus 10 comprises removable rack structure, not shown, that is adapted to support dishes and other utensils within the vat 12 for washing purposes, the rack structure being movable into and out of the vat 12 through the front openings when the front door 13 occupies its open position. An impeller 14 is arranged within a sump 15 formed in the bottom of the vat 12 and is rotated by an associated electric drive mo`1 vtor 16 disposed below the bottom of the vat 12 for the purpose of producing a washing action within the vat 12, when the front door 13 occupies its closed position and wash water is contained in the Asump 15.

For the purpose of supplying wash water to the vat 7,12', there is provided an inlet conduit 17 that is adapted i to be connected to a suitable water supply system, such,

for example, as a hot water tank, by intervening pipe, not shown.

mally biased into its closed position and is operated therefrom into its open position by an associated solenoid 18a; whereby the hot water from the inlet conduit 17 isv sprayed downwardly from the spray device 20 through the vat 12, when ythe valve 18 occupies its open position with the solenoid 18a in its energized condition. When the solenoid 18a is subsequently deenergized, the valve 18 is returned back into its closed position in order to cut oft the supply of hot water to the spray device 20.

A drain opening 15a is provided 1n the bottom of the sump 15 and communicates with the intake port of a drain pump 21 that is driven by an associated electric motor 22, the pump 21 and the motor 22 being disposed below the bottom of the Vat 12 adjacent to the motor 16. The drain pump 21 is also provided with a discharge port that communicates with a conduit 23 that, in turn, communicates with a drain conduit 24 that is connected to drain plumbing, not shown.. The conduits 23 and 24 are arranged in upstanding relation between the rear Walls of the cabinet 11 of the vat 12, the outer end of the conduit 23 being downwardly turned and separated by a gap from the adjacent upper end of the conduit 24, the extreme upper end of the conduit 24 being provided with a funnel-like structure 24a disposed below the outer or discharge end of the conduit 23 so as to provide the previously-mentioned gap therebetween. When the drain pump 21 is at rest, water introduced into the vat 12 is accumulated in the sump 15; and when the drain pump 21 is operated by the motor 22, the water accumulated in the sump 15 is removed therefrom viaY l erably of the sheated helical resistance conductor type disclosed in 1J. S. Patent No. l,.367 ,341,`granted February Q PadtentedMar. 4, 1958 The inlet conduit 17 communicates with the inlet port of a valve 18; and the outlet port of the valve 18 communicates with a conduit 19 that is connected to a spray device 20 arranged substantially centrally in the top of the vat 12. The valve 18 is nor- Y26 is arranged in the bottom of the sump 15 in surrounding relation with respect to the impel1er71r4 for the pur-Vr` posesot'preventing'soilaccumulating ,inthewv sump; IS-,frombe1ng:throw11 zby theoperating; irripeller, V14A1 'backs into; Y

' theSupportedzdishesfina "washing;voperation. f

Further? the, `dis'lttwashing apparatus .10Q-ficomprsesr.-V a,

Y control; circuit 100; lshowpaiirljig.: 3;; that' includesf aLpr-QV s gram controller;` 101; thatisghoused; between the; cabinetf.

11s/"aud Vthe VYvat12,' therprograrnrlcontreller 101` beingr Y j providedY withj :ilrrianuarllyl operable. controlknob L or dial.

Y VthelVcabirietlatyl and readily'accessible-Jfrom thezexteriori:v

;A1so, thecontrolcircuitf100 cornprisesagdobrfswiteli163? housedl between-Alie: cabinet ll'and the vat V'I2 and 'sie-Y- lectively! operated inl. response to! opening: and11cil'os'i'ngjfo*if` 1L andi th'evratr'12,A and disposed adjacentftortheupper! right-.handfrc'ntY of thecabnetf 71:1 'and'f readilyj-Y visible the Telechron type provided with a drive shaft:l 108'- thatis-coniectedto {esea'peme'ntfrneehanism: 109 havin-gia drive, shaftl 110;A`r -VTIie'- prgranfi controller-f?101 :further compn'sesa; rotatablymountedfi operating shaft-111'", tlie carried-fbyflthe front offthe:v cabinet 11;*whereby VtheA co-v housed. withinl a; substantiallrlmhular tim-.S11anni,ACastillanYV 131 projectinglaterally from the valve'casing 121aand Vsealed thereto. The Ysolenoid-18aV is arranged;r in? sui-; rounding relation with respect to the tubu1ar'casing'1'31k 't er n and positioned so that when it isV d'eenergized the plunger 129Y is disposed generally outwardly with respect thereto ktoward the extremeYouterendifthe tubular'rca'sing 131.; Y Further, a,substantiallyireupsbaped yoke 1321s arranged in surroundingfrelatih witht r'feslgnlefcl:` to (the `solenoid 18u;V andan armature 133 is piyorally mounted non knife? f YFurther;1a-bracketslSisicarriedtbyjzheyokeIaxijzxeleilt *Y ci to the knife edge Y1314andini turn supports afnnmber Y' of vswitch springs, including theindiividaswitchYspringsYAY 141,:141 Y143 'and `144, the switch springs "141jand'i Y 143 constituting movable switch springs YAconnected* to an operatinwbe'twee the, indicia .mentioned' carried byftlre 1 skirt113; and 'tliehdeamarlrerf1f14indicates 'the'progress'A oftheiwashirgleyele; Vas explained Ymore fullyy hereinafter.

Also,,theoperatig-shaftllll `carries'eighfinsulatingetfm- Y trol cams-1 l(31410v C8, i-nelusive,` `thatl respectively l co- Y operate #with eig-ht sets' lofiswitch*springs S1' to, S8; inw' elusive; andnallyfthe inner end'of the operatingl shaftjfY 5 vlll'anl theouterr' Vend'cithedriveYV 'shaft 110 sarei op-z erativelyfin-terconneetedby ajslipclutch 1121of'the fiieif` tion plate-type'. e In thev arrangement, the operating shaft.,V 111 may be rotated independently ofthe drivejsh'aft 110A b'yl theemanual"l dial Y 1D2'fby Yvirtue of' the` interpositionY Y operatingV4 Vthe 'drive shaft 110y is driven stepfby-step'on'A a amebasisasa resnu/of'thefopernionofthe escape' Y ment-meehani'srn'109v-Yso th'atjthe .jxperating shaftflll is j' correspondinglyv driven j step-bystep 1 by the 'drive shaft Y' Y Referringnowto Fig; 4,ythelvalveg1-8"eonstitutesacomf `binec1= water-fcontrol ivalve and control switch,A Vandv corn-V Y prises aVaIVeu casing 11271providedjwithanY vinlet'pport"l 122 thatl 'isf connectiedtoithe conduitl 17 and an outlet Y portl 123-Ythrat-ris connecteditothe conduitf 179; `aswellas aninterior dividing wall* lzdhaving': a valve Yport'vv therei'n `with` whichv a 'iA/alve;V elementj126icooperateslrV More particularlyrthe valvecasing 121V'is-provided with a; Y

laterally extending tubular projeetion 127.* 'in which; there is slidablyfmou-nted .ia valve; stem `12Sthat*carrfieson its f inner l'end'tine/'valve element; 12.6 Qandj that carriesl on its Y j-throug`h`the sliplelutch 112: Specifically; the escape#` merit mechanism lf09isso constructedVV and1 arranged'that Y theV driveshaft 110VV is'` driven throu'gh av s'mallrangl'e offV outeriend ;a,p1unger 129;"the yalye element' V126" beingj '1 Vbiasedinto itsclosedpositionrwithgrrespect'tothefvali/e Y port bya coilE spring 130' 'arranged irrY compression between the-outerend 'of the tubular `projecticnti *HTI-RandV outerte'ndf rotj'thei v'valvejstern 12822arid?the;tubular Eprojec- 127;,"` thecoil'; spring .1302 and plungerV 129 arepositions: Y Y

insulating operatingelrement 115that ,bearsfagainstfanf operatingarnr1146gcarriedby-thefarxiiaturell su'ch,f for example; t 'as so'ftfirorrlj` Furthermore; thef'inn en d [of the'tubnl'ar casingv 131- is Hermetically sealed is' moved" outwardl'y in'- the- .tnbular casingI ljl'fbyj the;` coil spring'w 130 Yso Ythat VVthe vvalve V:sterrr 128? moves" thea" valveelementll inw@ clesedpcstisn-with www@ r-j f thievalve Portilzgthersbrroicut-oifcflieinlef orf. 122?" from vthe outlet port`123'; andthe'armature'.lisreieasei 'i so, it isY moved Yintov its restored'position' bythe resilientzyl Y' Stem.. .128.; According fheivalve c elem 12d actuating;

gain referring .to Fig. 3, the control circuit-100 furtherv comprises a source of power supply of 11S-volts A. C.v

and including two supply conductors 151 and 152 that are respectively grounded and ungrounded, as illustrated. One terminal of the door switch 103 is connected to the supply conductor 152 and the other terminal thereof is connected to a bus 153; the two individual switch springs of the set S1 are respectively connected switch springs of the set S4 are respectively connected to the bus 153 and to a conductor 158; the two individual switch springs of the set S5 are respectively connected to the bus 154 and to a conductor 159; the two individual switch springs of the set S6 are respectively connected to the buses 153 and 154; the two individual switch springs of the set S7 are respectively connected to a conductor 160 and to the conductor 156; and the two individual switch springs of the set S8 are respectivelyA connected to two conductors Y2 and X2. The solenoid or winding of the measuring coil 104 is connected across the conductors 155 and 158; and the measuring coil 104 is provided with a pair of contacts respectively connected to the conductor 156 and to a conductor 161, the contacts mentioned being governed by a contact bridging member 104:1. The pump motor 22 is connected across the conductor 157 and the supply conductor 151; the main motor 16 is connected across the conductor 158 and the supply conductor 151; the heater 25 is connected across the conductor 159 and the supply conductor 151; the timer motor 107 and the run pilot lamp 106 are connected in parallel relation across the bus 154 and the supply conductor 151; and the solenoid 18a is bridged across the conductor 161 and the supply conductor 151. The pushbutton switch 105 comprises two contact bridging members 105 and 105" that respectively govern associated Y pairs of contacts; the contacts of the pair governed by the contact bridging member 105 are respectively connected to the conductor 160 and to the bus 153; and the contacts of the pair governed by the contact bridging member 105" are respectively connected to two conductors X1 and Y1. Further, the switch springs 141, 142, 143 and 144 respectively terminate the conductor 160, the bus 152, the bus 154 and the bus 153.

In the arrangement, the cycle pilot lamp 107 is of the gaseous discharge type, preferably a neon lamp. Further, the control circuit comprises two resistors R1 and R2 connected in series relation by a conductor 162 and bridged across the bus 153 and the supply conductor 151; and the electrodes of the cycle pilot lamp 107 are respectively connected to the opposite terminals of the resistor R2. Finally, the opposite terminals of the resistorvRl are connected to two conductors X and Y that may be respectively connected either to the conductors X1 and Y1 or to the conductors X2 and Y2. Thus, as explained more fully below, itis contemplated that the cycle pilot lamp 107 may be controlled by either ofthe alternative arrangements mentioned; and depending upon the connection of the conductors X-Y to the conductors X1-Y1or to the conductors X2-Y2.

In the control circuit 100, when the program controller 101 occupies its normal or home position, the sets of switch springs S1, S2, S4, S5, S6 and S8 occupy their open positions and the set of switch springs S3 and S7 occupy their closed positions, the heater 25 is deeuergized, the timer motor 107 and the pump motor 22 and the main motor 16 are deenergized, the pushbutton switch 105-occupiesits open position, the solenoid 18a is deenergized so that the valve 18 voccupies its closed position, and the measuring coil 104 is deenergized so that the bridging member104a occupies its closed position. Atjthis time,y the position of the door switch 103 is governed by the position of the front door 13, the doorA switch 103 occupying its respective open and closedpositions when the front door 13 occupies its respective open and closed positions. Finally, at this time the run pilot lamp 106 is extinguished indicating that the washing cycle is not in progress, the cycle pilot'lamp 107 is extinguished indicating that a washing cycle hasnot just been completed, and the indicia carried by the skirt 113 I of the manual knob 102 cooperates with the index marker 114 to indicate that the program controller 101 occupies its oi position.

The mode of operation of the dishwashing apparatus 10 and the time-sequence of operation of the elements incorporated in the signal and control circuit will best be understood in conjunction with the following description of the washing cycle of the apparatus.10, and it may be assumed that the dishes are supported by the rack structure, not shown, arranged in the vat 12, that a charge of a suitable detergent has been placed in the pocket 13a provided in the inner wall of the front door 13,'and that the front door 13 occupies its closed position effecting operation of the door switch 103 into its closed position. When the door switch 103 is thus operated into its closed position, the supply conductor 152 is connected to the bus 153 and thus via the resistors R1 and R2 in series relation to the supply conductor 151. Accordingly, the line voltage is connected across the resistors R1 and R2 in series relation, whereby the .initial voltage drop across the resistor R2 is applied across the electrodes of the cycle pilot lamp 107. However, the cycle pilot lamp 107 is not illuminated at this time, since the break-down voltage thereof is greater thanthe initial voltage drop across the resistor R2.

At this time, the operator initiates the cycle of operation of the apparatus 10 merely by momentarily operating the pushbutton switch and inthe present instance, it may be assumed that the conductors X-Y are respectively connected to the conductors Xi-Yl; whereby the contact bridging member 105 short-circuits the resistor Rlso that the line Voltage is applied across the resistor R2, which line voltage is greater than the breakdown voltage of the cycle pilot lamp 107, so that the discharge through the cycle pilot lamp 107 is initiated producing a glow or illumination thereof. When the pushbutton 105 is subsequently released, the contact bridging member 105 removes the short-circuit around the resistor R1, whereby the line voltage is again supplied across the resistors R1 and R2 in series relation,r so that the initial voltage drop again appears across the resistor R2; and while this initial voltage drop across the resistor R2 is below the break-down voltage of the cycle pilot lamp 107, it is above the sustaining voltage thereof, whereby the discharge through the cycle pilot lamp 107 is maintained so that the illumination of the cycle pilot lamp 107 is maintained subsequent to the release of the pushbutton 105.

Also when the pushbutton 105 is momentarily operated, as noted above, the bus 153 is connected to the conductor at the contact bridging member 105 thereof; whereby a start circuit is completed for energizing the solenoid 18a; this circuit further includes the closed set of switch springs S7, the conductor 156, the contact bridging member 104a, the conductor 161 and the supply conductor 151. Accordingly, the energized solenoid 18a effects opening of the valve 18 and closure of the switch springs 141 and 143 with respect to the switch springs 142 and 144 in the manner previously exv plained. The closure of the switch springs 141-142 completes a multiple path between the bus 153 and the conductor 160; whereby the subsequent release of the pushbutton 106 and the consequent operation thereof into its open position is without effect in the subsequent 1 operation of the control circuit 100. At `the-switch i springs 143-7144 the b us 1 5`3lis connected to the busy.,

9., switch.' 103 and the supply conductor 152. Accordingly, at'this time, the heat generated by the heater 25 is supplied to the charge of wash water in the vat 12 by virtue of the fact that the wash water cornes in contact therewith as it is thrown about in the vat 12 by operation of the impeller 14; and in passing, it is mentioned that the normal level of thewash water contained in the sump 15 isin fact well below the horizontal position of the heater 25. This addition of heat to the wash water in the vat 12 prevents the normal tendency of cooling thereof as a consequence of the finely divided condition thereof produced by operation of the impeller 14.

,In the next step of the operating shaft 111, the set of switch springs S2 is opened thereby further to interrupt the'previously traced circuit for energizing the solenoid 18a of the valve 18 so as positively to insure that the valve 18 is returned into its closed position independently of the operated condition of the measuring coil 104, thereby positively to insure that the maximum charge of wash water into the vat 12 is not greater than a predetermined amount, in the event of failure of operation of the measuring coil 104; which predetermined amount corresponds to that which may ow through the spray device 20 in the two steps of the program controller 101 during which the set of switch springs S2 is closed, as previously explained.

The rst washing step proceeds through a plurality of l steps of the program controller 101, as indicated in Fig. 5, whereupon in the tenth step thereof the sets of switch springs S1 and S5 are opened, and the set of switch springs S3 is closed. The opening of the set of switch springs S1 interrupts thev series circuit for energizing the measuring coil 104 and for operating the main motor 16;v whereby the contact bridging member 104:1 is reclosed and operation of the main motor 16 is arrested to stop the impeller 14 at this time. The opening of the set of switch springs S5 interrupts the circuit for energizing the heater and the closure of the set of switch springs S3 completes the circuit for operating the pump motor 22 so that the drain purnp 21 is operated to elect the discharge of the wash water from the sump 15 into the drain conduit 24, in the manner previously explained.

In the eleventh step of the program controller 101, the

sets of switch springs S1 and S4 are reclosed and the set of switch springs S3 is opened. The opening of the set of switch springs S3 arrests operation of the pump motor 22 and consequently of the drain pump 21; the closure of theset of switch springs S4 completes the previously traced direct circuit for operating the main motor 16; whereas the closure of the set of switch springs S1 prepares the se'ries circuit for'operating the main motor 16 via the measuring coil 104. Thus at this time, operation of the main motor 16 is resumed, whereby the impeller 14 is again operated.

vIn the twelfth step of the program controller 101, the setV of switch springs S2 is closed and the set of switch springs S4 is opened. The closure of the set of switch springs S2 effects energization of the solenoid 18a so that the valve 18 is again operated into its open position bringing about the supply of hot water into the vat 12; and opening of the set of switch springs S4 removes the short-circuit around the measuring coil 104 so that at this time the main motor 16 and the measuring coil 104 are energized in series relation. Accordingly, at this time the measuring coil 104 again meters the quantity of hot water that is supplied into the vat 12 and is ultimately operated to effect deenergization of the solenoid 18a and the consequent return of the inlet valve 18 back into its closed position, in the manner previously explained.

In the thirteenth step of the program controller 101, the set of switch springs S5 is reclosed so as again to effect energization of the heater 25 and the consequent supply of heat to the present charge of wash water being introduced into the v at 12. program controller 1 01, the set of switch springs S2 is In the fourteenth step of the opened, in order to insure the return of the inlet valve 1S into its closed position, in the manner previously explained. This second washing step proceeds in the manner previously explained until the program controller 101 is driven into its eighteenth step effecting opening of the sets of switch springs S1 and S5 and closing of the set i in the twenty-four through the twenty-eight steps of the z program controller 101; which third and fourth washing steps are entirely similar to the lirst and second washing steps described in detail above, but are of slightly shorter time duration as indicated.

Accordingly, in the twenty-ninth step of the program controller 101, only the sets of switch springs S4 and S6 are closed, whereby the main motor 16 and the timer motor 107 are operated; and of course the timer 107 is operated and the run pilot lamp 106 is illuminated. In the thirtieth step of the program controller 101, the set of switch springs S5 is closed so that the heater 25 is againvenergized. At this time the air in the vat 12 is circulated by the operating impeller 14 through the dishes supported by the reticulated structure, not shown,

and over the energized heater 25; whereby the dishes are subjected to a drying action by a blast of hot air. The above described drying step proceeds through a time interval and until the program controller 101 is driven into its fifty-ninth step; whereupon the set of switch springs S4 is opened to arrest operation of the main motor 16.

Accordingly at this time, the supported dishes are merely heated by the energized heater 25 toV eiect further dry' ing thereof, and without the blast of hot air, since the impeller 14 is not further operated. This static drying step proceeds through the remainder of the cycle of the program controller 101, as explained more fully below;

and when the program controller 101 is driven into its.

seventieth step, the set of switch springs S7v is reclosed.

This reclosure of the set of switch springs S7 is without X2-Y2, instead of'to the conductors X1--Y1 in accordance with the present assumption; whereby this arrangement is without effect in view of the present assumption.

Whe-n the program controller 101 is driven into its seventy-second step, that also comprises its home or zero position,l the sets of switch springs S5, S6 and S8 are opened, the set of switch springs S7 is. retained in its closed position and the set of switch springs S3 is reclosed. The opening of the set of switch springs S5 interrupts the circuit for energizing the heater 25 so as to terminate the static heating step mentioned above; whereas the opening Aof the set of switch springs S6 disconnects the bus 153 from the bus 154 so that further operation of the timer motor 107 is arrested and the run pilot lamp 106 is exi tinguished. Accordingly, at this time, the composite cycle of the dishwashing apparatus 10 has been completed; however, the cycle pilot lamp 107 remains illuminated so long as the frontv door 13 occupies its closed position since the supply conductor 152 is connected viavthe door switchi cycleepiiot lampV 107, ae previqnsly'-expiamedef Hence, 55

the illmination" o f theY cycle pilot lamptl 'atter'the'rnn `pilot lamp 106;V isgextirlgui'shed; serves to indieate thatgtltief` ing-cycle: At" this'time,p the controlircuit 100"occupiesk tutti; not shown,

tion; the doorv switch510`3" isA operatedglintaits openpos'i-j circuit 100 into its initialr condition. l

r`tion 'inorder'todisconnectthe supply conductor 152 f rom the'bus; 153 sonas" to bring abont'extngtiishingfoflthei cyclepilotv lamp 107 and the restorationv of the;'eontrolv n'thenext`-cycl e of operationl o f the dishWashing'ap-f paratus'10','the-returnofttie'front door 13 into its closed` position again"op.erates'th e door switch 103 so as again` i to'econnect'tlie supply conductorj 152 to the bus 15 3 .andfj so-` as to--render'effective'thepushbutton switch 105'; where'- by 4 theicycle of`V the dishwashng apparatusV 1 0 may' be Y again* initiated ir'r response; to another momentary opera- Vtion of the pushbutton 10'55 'i'n the "manner explained;Y

' above. In passing, itis mentioned that'lwhen Yihf1 1911tVIA door-llisagainreturned into its closed position effecting 1 Yreoperat'iojn'of'the doorswith 103ir1to` its cl'osed'posititm,`

is'greaterthanthe initial voltage drop yacross the resistor Vwithtlieresistor; R1, as previously explained.

Y the-*cycle1` pilot lamp 107 Yis not illuminated immediatelyr by :virtue of the fact that the break-down voltage thereof 'In the foregoing'explanation'ofithe mode of.operation of`tlie control circuit 100, vitlw'a's assumedfthatthejeonductors';'X'--Y'wer e respectively connectelto thefconfductorsXI-#Ylarid now it is assumed that instea'd'tlie` i control j circuit 100l i sl slightly modiied, but only Ywith 'refV spectto' the time at' which Ytlie cycle 4pilot lampf 107'. isr illufrnirl'ated.`V fln the presentcase, the momentaryopera- Q tionoffthe .puslbu'tton 1051's Withonteffect withrespertv` t to the i11umnationfof the cyclepilot -10 7, sinceitQ is assumed that the condctorsXl-Yl are open; where bygthe remainder of thecyclef-of thencontrolV circuit/100V is thej same-Jas 'Y that. previouslydescribed. However, in `r` f the; presentcase, whengthe: programY controller 1011isA g t drivenginto itsfseventy-rst step, the. closure. of they set; ofi

' switchlsprin'gssetfects theirshort-circuitingofl 'the1r'es`is.--

torir;11,.;wherebythe voltage drop across' the resistor R2 :is increased terbring abouttlie break-down of the-cycle pilotllamp 107.' Inthisfcasegwhen the-program con-V Y troller 101 is returned back into .its home position, the Y i' opening of theset of'switclhsprin'gs S8 merely inserts the VresistorRIagaiifr in vs'eries'with the resistor R2, whereby Y the voltage drop across the reisistor R 2 is above the sustainikngzvoltage of thecyclerpilot lamp 107 so that the, Villinriination of 'the cycle pilot lamp `1 07" i s maintained l after the program ,controller 101 is returned back into fitsho'me position, 'the` illumination of the cyclefpilotV Y Y lampif'107, without the. concurrent illuminationof therun l pilot Ylamp 106,:servinglthegsignal purpose previouslyY explained: y .Y Recapitulating it is pointed; outv that when the: clon;

of cycle-foi operation .ofthecontrol circuitA 100;. onv

' cuit' 10": However, ineifherfcaselme;cyciepilt 1mi* the; 'gnalipnrpose described." jV

' turesroftthepresent:inventiongthe arrangement 35 it `vvillg be linderstood that the :fundamental cycle thereof R2ggwlientheiresistor R2is energized in series relation the conductorsv X'- Y areconne cted'togethernajcircuitis v vionsly explained; Yiiqhere'byj-tlie'- cyclerelY y `106 Vfis retained `illuminatedvv` only duringjthef cytlc fqff 'epe eration-of the control circuit-100;whereby in eitlier'c y the cycle pilot .lanlp'107,;when illuminat withoutthe cncrrent Villumination of-:the rnn'piltlam 06," 'i

2 armes coi-dance with thei alternative arrangements previuslyj-fjV completedjgforv energizing the 'Windingot .thejcycle rel' XZj-YtZgin the alternative arrangements., ,theicyclelrelayg 601 isv retained eine its operatedv P Qtn by. tvirtlieofl the "cycle of theeontrol circit-600forgthe-pnrposepreviosly' f i` turned` infix Vtsjonell. position; edbplrj 13V as that previously described in conjunction with the control circuit lub.

In view of the foregoing, it is apparent that there has t been provided in dishwashing apparatus, an improved signal and control circuit that is arranged to eiect an automatic cycle of operation thereof and selectively to present signals to the operator indicative of the progress of the automatic cycle so that the operator may readily discern when the automatic cycle is in progress and when the automatic cycle has been completed, all without actual inspection of the interior of the vat or the dishes therein. The arrangement is very advantageous as the operator is provided with appropriate signals so that she may instantly distinguish between a rst condition of the dishwashing apparatus when the same is at rest because the cycle thereof has never been initiated following the loading of the vat with the soiled dishes and a second condition of the dishwashing apparatus when the same is at rest because the cycle thereof has been completed following the loading of the vat with the soiled dishes; whereby the signalling arrangement renders it unnecessary for the operator to remember whether the cycle has been initiated following the loading of the vat with the soiled dishes. The arrangement is particularly advantageous when the load of dishes consists essentially of drinking glasses as it is frequently ditlcult even upon close inspection for the operator to determine whether the drinking glasses have been washed following the last use thereof, and since it is obviously desirable to wash tllie drinking glasses even though they are apparently c ean.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. A signal and control circuit for dishwashing apparatus including a dish-receiving vat having an opening thereinto and provided with a cooperating door movable into openand closed Vpositions with respect thereto; said circuit comprising, in combination, a program controller having a home position and a plurality of control positions, a manually operable start member operative to effect operation of said program controller out of its home position, automatic means controlled jointly by said door in its closed position and by operation of said program controller out of its home position for effecting operation thereof in a given timed cycle through its control positions and back into its home position, means selectively controlled by said given cycle of operation of said program controller through its control positions for operating said dishwashing apparatus through a given dishwashing cycle, a run pilot signal, a cycle pilot signal, a pickup circuit for operating said cycle pilot signal, a hold circuit for operating said cycle pilot signal, means responsive to movement of said door into its closed position for preparing said run pilot signal and for preparing both said pickup circuit and said hold circuit and responsive to movement of said door into its open position for arresting operation of said run pilot signal and for interrupting both said pickup circuit and said hold circuit, means responsive to operation of said program controller out of its home position for initiating operation of said prepared run pilot signal and responsive to operation of said program controller back into its home position for arresting operation of said run pilot signal, whereby said run pilot signal is operated during operation of said programcontroller and thus serves to indicate when operated that the dishwashing cycle is in progress, means controlled at a predetermined point inv said given cycle of operation of said program controller for completing said prepared pickup circuit, and

means controlled by completion of said pickup circuit for completing said prepared hold circuit, whereby said cycle pilot signal is retained operated after operation of said program controller backV into itshome position so that said cycle pilot signal thus serves to indicate when operated without concurrent operation of said run pilot signal that the dishwashing cycle has been completed.

2. A signal and control circuit for dishwashing apparatus including a dish-receiving vat having an opening thereinto and provided with a cooperating door movable into open and closed positions with respect thereto; said circuit comprising, in combination, a program controller having a home position and a plurality of control positions, a manually operable start member operative to effect operation of said program controller out ofrits home position, automatic means controlled jointly by said door in its closed position and by operation of said program controller out of its home position for effecting operation thereof in a given timed cycle through its control positions and back into its home position, means selectivelycontrolled by said given cycle of operation of said program controller through its control positions for operating said dishwashing apparatus through a given dishwashing cycle, a run pilot signal, a cycle pilot signal, a pickup circuit for operating said cycle pilot signal, a hold circuit for operating said cycle pilot signal, means responsive to movement of said door into its closed position for preparing said run pilot signal and for preparing both said pickup circuit and said hold circuit and responsive to movement of said door into its open position for arresting operation of said run pilot signal and for interrupting both said pickup circuit and said hold circuit, means responsive to operation of said program controller out of its home position for initiating operation of said prepared run pilot signal and responsive to operation of said program controller back into its home position for arresting operation of said run pilot signal, whereby said run pilot signal is operated during operation of said program controller and thus serves to indicate when operated that the dishwashing cycle is in progress, means controlled by said program controller in a given one of its control positions for completing said prepared pickup circuit, and means controlled by completion of said pickup circuit for completing said prepared hold circuit, whereby said cycle pilot signal is retained operated after operation of said program controller back into its home position so that said cycle pilot signal thus serves to indicate when operated without concurrent operation of said run pilot signal that the dishwashing cycle has been completed.

3. A signal and control circuit for dishwashing apparatus including a dish-receiving vat having an opening thereinto and provided with a cooperating door movable into open and closed positions with respect thereto; said circuit comprising, in combination, a program controller having a home position and a plurality of control positions, a manually operable start member operative to effect operation of said program controller out of its home position, automatic means controlled jointly by said door in its closed position and by operation of said program controller out of its home position for effecting operati-on thereof in a given timed cycle through its control positions and back into its home position, means selectively controlled by said given cycle of operation of said program controller through its control positions for operating said dishwashing apparatus through a given dishwashing cycle, a run pilot signal, a cycle pilot signai, a pickup circuit for operating said cycle pilot signal, a hold circuit for operating said cycle pilot signal, means responsive to movement of said door into its closed position for preparing said run pilot signal and for preparing both said ing operation of said run pilot signal and for interrupting A itsfrhometposition for ,initiating operation ,of said prepared "j V- completingrfsaid prepared pickuprcrcuit, Vandrneans con,-V` 1 Y trolledby completion of said pickup circuit for complet-Y "Vinggsaid prepared hold circuit, Ywhereby*,saidcyclegpilotV signalisfretained operated afterl'operationA of lsaid pro- Vhavingfaihome positionand a plurality oficontrol"posi-v 'Vtions, a Ymanually operableV startV member` operativefto Yeliect operation of said program controller"outjofits.

v operating said i dishwashing apparatus thr'gugh.'` Y Y dShWaShHg Cycle, avrunplot signaLa gaseous discharge Y35 operation 'of said program controller back into itsj'home ingf atfleast ra portion Y'ofrtheother or saidjresistgr Y that ,the Vvolta*ge-.dropacrossfsaid one resistor VAi's incijeas d signal that the dishwashingffcylejha'si'been completed.

y t bothlsaid pickup circuiti.andjsaidfholdcircuit;nfieansrai YSpdll'sye to operatipn of`said 'programcontroller outof'"` run pilot signal and'responsive to operation of saidpro? Y gramY controller back intro its home position foi-arresting f5 Aoperation of said run pilot signal, wherebyy said run pilot- Y signal is' operated'during operation ofsaid program con.-

trollerV and thusrservesA to indicate when operatedfthat- Y the dishwashing cycle is in progress, means. responsive'to fr operation ofV said manuallyfoperable". start member for k10 gram controller back into its home position so'thatisaidi Vwithout concurrent operation ofs'aidfrun pilot signaljthat Y the'dishwashing cycle has been'cornpleted.V Y

A signal andcontrol circuit fordishwafshingappara- Y tus including a dish-receivingY vat havingian Vopening*- 1 thereinto and provided with a cooperating fdoor 'movable into open and closed positions Vwith respect theretofsai'd circuit comprising, in combination, a programontroller home position, automatic means controlled jointly'pby'spaid door in its closed position and" by Operation'oflsaid pro'- gram controller out Vof'its home positiouffor' etlee'ting` operation Vthereof in a given,timedjcypcle throu'glitsv coni4 trolA positions, and `back jinto Vits Thome` positiongumean's Y selectively controlled by said given cycle of'operatioupfjl said program. controller through its"control positions ,fori

given."

tube 'productive ofa glow when condlflctiveL,al` fcircuitin cluding two seriesrconnccted resistors, said tube beinggc .i ne/c'tedfacrossV oneof1v said resistors, means responsive' to 'movement of said'door' into its closed, position Afor.' preparing said ArunV pilot fsignalgand for completing said circuit andfre'sponsv to movement of 'saidnrdo'or into itsl l openposition torrairrersting operation Vofrzsaidwrun pilot signal Vand for interrupting said jcircuit;.therbreakldown` voltag'eiof'said tube' @being greatenthan theV norrlrnal'yoltiY age-drop across saidjone resistor whensaid circuit isirtllp'spfwV fcompleted, means 'responsive to operation of saidpro'gi'amr 'v `controllerout of itshome position for initiating opera-A tin of said preparedrunpil'ot signal'gand*responsive to position for Varresting operation Yof 'said/fluir pil9tsi'gna1` of 'said program icontroller and"thusgserves' ,toV indicate o Y,when operatedthatthe'dishwashing'lcyle is nrprogressf Y t Y' and means controlled' atV a predetermined? panini;V `11ja1-g given cycle of operation of vvsaid program `controllei;for f5 colmpleting'and then for interrupting` afpathjshortl-circu toarrvalue greaterrthansaid break?down',voltage; Y 'saidV tube and then reducedback,togsaid'norrnal 'voltagestliref* sustainingfvolt'age of said tub 'beigles's than said voltage, y whereby said tabla` Y i operation of said -prograin` contrcp-)ller` linfo *itsk Vlio conductive without concurrent' operation o f saidrunfpil 5K. `Afsig'nal and controlcircuitffor dishwas/hing'xapp'ara K' tus, including'.Y afldishreceivngu'vatl having'` 1an. opening thereinto, `and providedYY with al;'ooperatingjoorA modaal? 70 Vinto'opeu and `closed positionsY with,respecttheretogsaid cireuitfcomprisingrin ibiilatan, a] wat@ Qrf'ffllerr having. ahome f position, and a plurality 'of Ycontrol posi-1v tions,amanuallyoperable start membergoperativerto etfe'et-l y v Voperation;oitsaid program' controller outoff'itsMhoine-v-Y position, "automatic means ft and saidholdtclr Y15'y cyeleipilot signal Ythus serves to indicatie when operatedUY i tus including a dishfreceivingvat:having an openingthere Y into Yand 'provided with fa cooperating Ydoor movable'- 1Ynto Y 'of-said program controllerfor time 'cont/rolled byA s gram' @mannaggiamm1 'positions ffof para@ dishwasllinggapparatus@througha'given dishwfslrL 1 Y `foi-'initiating,operation,of said' prepared` run pilot sigualV 20j t 'andresponsivejto operation ofsaid program'controllerl backinto'its home ypositim forarresting operationof saidVV run p ilotlsigpalggwhereby saidgrungpilotjsignal,is operated". during operatic@ of"'isaid/program-iV controllergiand jthusr` Y* j serves` toji'ndicate -when` operated,thatthedishwashingl r cycleV 1 invtpkrogressgmeans contolledi'atia predeterminedV d prepared pickup4 circuit, whereletinghsal Y Y n means controlledlby operation z' n' wherebyi Sad relay `isf retained operated' ait'ersopeation:`V Y of saidrroaram c ontrgllenbakinto.its 1101116, PQSOIL'J a cycle' pilotj gnahaudmeansresponsivetooperation as seyes @i dica@ when@ s said 'runpilots'ignal lf' that the dishwashing cycle' has been,

*6. The signal and'control circuit combinati beginning thereof.;V

7. Thesignalafl t o r o ingclaim 1;, wherein: gprs@ erminedrgitihSeidlSiYee' f cycle t oi'operation o1said1pr'o`gram Ycontrollerlis ynear s; A signal ma rmirrorliprvegtlforaisha/suingappara" open andclosed positionsiwithfrrespect "theretoj s'aidfcir--f'V havingY a home positionndj a plurality-of controjlpo'si tions, va1 manually operable` start `memberjoperative.Y to f effect operationY offrsaid,Program-controllerlout ofi-itsg ,v Y home position, automatic-'means controlled(jointlyfzby`VVV I Y operation thc'r'eofin a given tuned `cycle througliiitsfcon Y rltrol''positionsjandbaclinte!"itsflhornefpositiori Vrneans'g; g Y selectively controlled by said-'given'cycle'vooperationof Y K said program 1controller',tlnfoligl-1l coptrol Vpositions for operating' said dishwashing jap'paratus `through* a l. given o t Y Y dishwashing' cycle; aniele'ctro-'responsivre-runlpilot signal,VY

means for operating saidirun piloty signal only concur-, V

rentlywvith operationk of said; prograirrcontroller through Y said given `cy`cle,`whereby Vsaid :run .pilot signal yvhen op,- erated indicatesethatthe ,dishwashng cycle `1s v in progress, Y

Y aielectro-responsive cyclezpilotpsignal, means controlled,v f K at a predetermined .po-int: in ,Saidjgiven rcycleof operational" itating l operation AofY Said; Y'

' pilot fsignallwhen operated lWithQutf. Concurrent, operation M, p of said .runpilotisignaljndaates both that `the 'dishwash Y*ingacyclerhas .beerircompleted since-said door was last;Av

' fof 9139i ating Sa'dfrelayi means responsive tojmovement'' Y Y n Y ofsaiddoor into: 1p Y Y nrsertlfroi'gtll l o Vin claim l, wherein lsaid predetermined Ypoirltfiuirsaid ,givenV l vcyile" of operation'f'saidprogram/controller snearfthe Y whereby Ysaid vrunjpilot, signal is peratedduring' operation o f`sai'c1v`d0or.inits'.losedipositiorrandfbyolzierationot-saidill vl VKProgr-arri. vControllerpout4 of *its home position for effecting. i

' 17 18 moved into its closed position and that since the cornple- 2,236,429 Hipsley Mar. 25, 1941 tion of the dishwashing cycle said door has not been 2,624,352 Illian Jan. 6, 1953 moved again into its open position. 2,671,455 MacDonald Mar. 9, 1954 2,707,961 Geiger May 10, 1955 References Cited 1n the le of this patent 5 2,710,010 Lengvenis June 7, 1955 UNITED STATES PATENTS 2,097,335 Memmel Oct. 26, 1937 

